Manufacture of steam-generator shells, cylinders, &amp;c.



- No. 700,360. Patented May 20, I902.

B. F. MGTEAR. MANUFACTURE OF STEAM GENERATOR SHELLS, CYLINDERS, 8w.

(Application filed June 19,1900.) (N o M o d 0] ts-Sheet I.

mm, I ms/4m 444 r 211% ATTORNEYS No. 700,360. Patented May 20, I902.

' A I B. F. McTEAR.

MANUFACTURE OF STEAM GENERATOR SHELLS, CYLINDERS, &.c.

(Application filed June 19, 1900.)

(No Model.) 3 Sheets-$he0t 2,

WITNESSES:

A I I 'nrronusrs Tu: ubmus mans ca. rum-human msmnn'rcu. n. c.

. Patented Ma an, I002;

B. F. McTEAR. MANUFACTURE OF STEAM GENERATOR SHELLS, CYLINDERS, 800.

(Application filed June 19, 1900.)

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WITNESSE s:

Anomrs.

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" UNITED; STATES:

] VBAiLFOUR FRASER iv'lcrnila, OFTRAI'NTHILL,ENGLAND! MANUFAQTURE?OFTSTEAM-GENERATOR. ums; crimes; at 1 SPECIFICATION-formingpart ofliletters Bate'nt lvi yrcoceo, dateolMay 1902. v "Applicatioufiled June 19,1900. semina'zases'. (NomodeL) Ton/ll whom it-mmyboncerjn: 1

Be itsknown thatLBALFOUR FRASER Mo- TEAR, a subject ofthe Queen of England, and

a resident of Rainhill, in the county of Lancaster, England, have invented certain new and useful improvements' in and connected with the manufacture of steam generator, shells, cylinders, furnaces, and otheranalogous hollow articles, partly applicable toother purposes, of which the following is a-speci fication.

My invention has reference to the manufacture of shells, flues, or cylinders of steam-v generators' and other analogous article's.

In the ordinary way the shells of stearngenerators are formed of'plates curved to the thicknessof shell-plates;'flrior, however, to

required shape and connected together by: means of longitudinalv and circumferential linesofrivets. It hasfbeenfdetermined by.

eminent authorities'fthat"the best system of riveting weakens" the "plates one-fourth or even more and thatj'if the 'longitudinalseams could be avoided an augmentation of pressure to the extentpof 'aboutrtwenty-five. per

cent. would be permissible with the-same i the present time it has been proposed to make cylinders or rings ,of'met-al withoutjoint; seam, 'or weld by a rolling operation from any ingot of steel or from a bloom or mass of metal similarly as inthe rolling of railway tires. i The proposed method-'ofpreparing'the I ingot or bloom forthe rolling operation conysisted informinga hole-init'by'a steam-hammer and placing it on a, mandrel and then hammeringlit in a swage; It.hasalso been i suggested to take a'cast'hollow cylinder ingotand forge ittothe right size.; For effect- I ing the purposes of;the present invention these proposals are practically usele'ssor offer very considerable difficulties in the manufactureu To treat a block of metal of a size and weight suitable for making-boilershells or flues in the manner proposed itis hardly if at all practicable and in any. event extremely difficult, andto roll, as has been proposed, a

number of shells or fines direct from prepared ingots orbloomsroan exact diameter and thickness, such asare required in'practice, is next to impossible.

According to this invention the objections and difficulties above referred to are overcomeg'a'nd the manufacture of seamless boiler hammered or cast'to any desired shape in cross-section and having the requisite mass or weight to produce a shell or cylinder of .thereqnired size, and this ingot or bloom in a white-hot or glowing state is placed in a die and piercedsay by hydraulic pressurelongitudinally while held infthis die,- thepiercing being effected bya conicaljor bulb- 'ous'pointed' mandrel-or tool. 7 The effect of this action, besides the formation o'f-{t'he immature hollow'cylind'er or'shell,"&c., is to compress and condensethe metal'and also in} 1 some cases to elongate the body. to'the length required. Thus thecqnality of-the-metal is improved, as the pressure caused bythe piero ingcloses up all holes and por ous places which mayexist in the ingot or bloom and generally compresses the meta'h Thehole'will -be "of 3 "considerable size'a'nd' is effected by oneipa'ss of the mandrelof-"thesize required orty con .s'ecutivepa'sses of mandrelsof different sizes.

The immature cylinder or article after removal from the die-in which it is p'ier'ced is 1 without"reheating, orafter beingk freheated rolled out by suitable'inside and outside rollfinished t th QXactfthick-V I ness of ring-plate required,l( this excess of size being allowedfor in the' ingot or bloom byemploying; a bloom or ing'ot of greater weight than the finished article,) 'and'th'en length byrolling on the outsidevl; er, externally-by a plurality of rol'lsarranged at different parts around it, the thickness'of the plate remaining the'samei,

In order to be useful for employment in the manufacture of steam-generator shells,

furnace-flues, and the like;- it is necessary that the shells or cylinders of which they are comprised be quiteaccurate as to diameter of the cylinder and also as to the thickness of the plate, and these two conditions and this extra metal in the formof excess: of dia ameter is reduced I and; converted in'to extra,

characteristics are readily accomplished by the method or process of manufacture or improvements according to my invention.

Machinery by which the manufacture of cylinders or equivalent bodies, as described, accurate both as to diameter and also thickness of plate, can be carried out advantageouslyis illustrated in the annexed drawings.

In the drawings, Figure 1 is a side elevation, partly in section; Fig. 2, an end View, partly in section; and Fig. 3 a plan illustrating one modification.

Like letters of reference are used to denote the same or equivalent parts wherever they occur in the drawings.

Regarding the machine illustrated in Figs. 1 to 3, this is adapted to reduce the cylinders in diameter, forcing the metal consequent upon reduction into length in such cylinders.

Referring to the drawings, :1: represents the cylinder being operated upon. This cylinder is supported upon a roller-bed at each side of the reducing mechanism, consisting of two parallel sets of rollers a, the shafts a, sup porting these rollers,being supported at either end by bearings 12, such bearings being mounted on the slides I), supported in the guides 11 The slides 11 are worked up and down in the guides b by screw-gear in any suitable known way.

The mechanism which operates upon the cylinder at comprises an annular frame 0, having a plurality of guides c therein, the axes of which are arranged radially through the center in the frame. In these guides 0" rectangular slides (Z fit and work, and these slides carry at their inner ends rollers 2, arranged in skew disposition. The slides 61 are worked up and down in the guides c by screwed shaftsf, meshing with threads in said slides, and tooth-wheels g on said shafts. All the wheels g and slides d are worked in and out, as required, simultaneously by a toothraek h, mounted on the frame 0 and operated by either of the two hand-wheels 2', each of which is mounted on one of the spindles or shafts f on either side of the machine. When these hand-wheels 2' are worked one way, the rollers e are moved out, and vice versa. Two or more of the rollers e are mechanically revolved and act as motor-rollers for revolving the cylinderw. j represents the driving-shafts of these rollers, and they are adjusted laterally by moving their bearings 7c nearer to and farther from the center of the cylinder simultaneously with the movement of the slides (Z. This is effected by mounting the bearings 7t on the end of the slides similar to (Z, mounted in guides 7;, the said slides being moved in and out by spindles in which are worked from the hand-wheel t by a sprocket-wheel 1', fixed on the spindle f, carrying this wheel, a sprocket-chain Z and sprocket-wheels Z Z on the shafts 7.1 and the sprocket-chain Z connecting said wheels Z Z-. This gearing for the driven wheels 6 is provided on one side of the frame 0 only, the mechanism on the otherside of the frame being merely the rollerbed for supporting the cylinder 00.

Prior to the cylinder 00 being operated on in this machine it is rolled to the exact thickness required, but to a larger external diameter, which of course can be done by allowing greater sectional area in the block of metal from which the cylinder is to be made than is actually required in the finished tube. Then the diameter is reduced to that actually required by setting the rollers e inward at a radius less than the radius of the tube or cylinder to be operated upon-namely, to the radius of that of the finished cylinder requiredwhich transfers the excess of diameter into length without increasing or varying the thickness. In action when the tube is started under the rollers 0 these rollers, being on the skew and revolving,revolve the cylinderrrand reduce its diameter and move it longitudinall y as well, and as it is rev'olved it traverses over one or other of the roller-beds, the rollers a, revolving with it. The reduction of diameter may be effected by one passing or a plurality of passings under the rollers e.

\Vhatis claimed in respect of the herein-described invention is- 1. The process of manufacturing seamless metal cylinders of large size, and of thediameter and also thickness required, consisting of first producing a perforate seamless blank or billet from which the cylinder is to be made, then rolling said blank or billet circumferentially and increasing its external diameter until it is of larger size than the cylinder required, and then reducing this excessive size by rolling it circumferentially at points allaroundsimultaneouslyfrom one end to the other, while it is being revolved axially.

2. The process of manufacturing seamless metal cylinders of large size, and of the diameter and also thickness required, consisting of first producing a perforate seamless blank or billet from which the cylinder is to be made, then rolling said billet or blank until it is of larger diameter than the finished cylinders but of the required thickness, and then subsequently reducing the diameter by rolling it externally at points all around, in substantially the same transverse plane of said cylinder, from one end to the other, while it is being revolved axially whereby the excess of metal caused by the reduction is transferred into a longitudinal extension.

In witness whereof I have hereunto set my hand in presence of two witnesses.

BALFOUR FRASER MOTEAR.

lVitnesses:

J OHN I-IINDLEY WALKER, M10. D. BROWN. 

